1. Data Analysis Applying Mathematical Concepts to Chemistry

2. Units of Measure SI Units- scientifically accepted units of measure:

3. The Metric System

4. Metric Practice 623.19 hL = __________ L 1026 mm = ___________cm 0.025 kg = ___________mg Online Powers of 10 Demonstration: http://micro.magnet.fsu.edu/primer/java/science opticsu/powersof10/

5. Derived Quantities- Volume Volume- amount of space an object takes up. V = l x w x h (all in meters) V= m 3 m 3 is too large so cm 3 are used 1 cm 3 = 1 mL by definition

6. Temperature Scales

7. Temperature Conversions Degrees Celsius to Kelvin T kelvin =T celsius + 273 EX: 25 °C = ? K T kelvin =25 +273=298K Kelvin to Degrees Celsius T celsius =T kelvin - 273 EX: 210 K = ? °C T c = 273–210= -63°C

8. Scientific Notation A method of expressing very large or small numbers in a concise manner Requires 2 parts: – Number between 1 and 9.99999999… – Power of ten – EX: 5432.1 meters  5.4321 x 10 3 meters

9. Factor Labeling (Dimensional Analysis) Any number divided by itself is equal to 1 – 6/6 = 1 – 6 meters/6 meters = 1 Any number can be multiplied by one without changing its value – 5 x (6/6) = 5 – 5 x (6 meters/6 meters) = 5

10. Converting Units Through Dimensional Analysis Equal units divided by one another are equal to 1 1m/100 cm = 1 m/cm 100 cm/1m = 1 cm/m 50 cm x (1m/100cm) = 0.5 m 50 m x (100cm/1m) = 5000 cm

11. Practice Problems 12.5 eggs = ? Dozen 13.69 m = ? cm 13.69 km = ? cm 1.25 x 10 3 ft = ? yd

12. Multiple Step Factor Labeling 5.2 x10 3 yd = ? In 45 mph = ? ft/min 3.1 g/mL = ? Kg/L

13. Derived Quantities- Density Density- how much matter is in the volume an object takes up. Density = mass/volume D= g/mL

14. Determining Density Mass- measure in grams with balance Volume- – Regular shaped object: measure sides and use volume formula EX: rectangle  V= l x w x h – Irregular shaped object: water displacement

15. Density by Water Displacement Fill graduated cylinder to known initial volume Add object Record final volume Subtract initial volume from final volume Record volume of object

16. Graphing Data General Rules – Fit page – Even scale – Best fit/trendline – Informative Title – Labeled Axes How Does Volume Impact Temperature?

17. Accuracy vs Precision Accuracy- closeness of measurements to the target value Precision- closeness of measurements to each other

18. Percent Error %error = (accepted-experimental) x 100 accepted EX: The measured mass is 5.0g. It was predicted that the accepted value should have been 6.0 g. % error = 6.0g-5.0g x 100 = 16.7% 6.0g

19. Significant Figures Measurements are limited in their sensitivity by the instrument used to measure

20. Estimating Measurements Read one place past the instrument 35.0 mL is saying the actual measurement is between 34.9 and 35.1 mL

21. Why Significant Figures? Measurements involve rounding Multiplying/dividing or adding/subtracting measurements can not make them more accurate Provide a way to tell how sensitive a measurement really is… 5 ≠ 5.0 ≠ 5.00 ≠ 5.000

22. Recognizing Significant Digits 1. Nonzero digits are always significant – 543.21 meters has 5 significant figures 2. Zeros between nonzeros are significant – 505.05 liters has 5 sig figs 3. Zeros to the right of a decimal and a nonzero are significant – 3.10 has 3 sig figs

23. Recognizing Sig Figs 4. Placeholder zeros are not significant – 0.01g has one sig fig – 1000g has one sig fig – 1000.g has four sig figs – 1000.0g has five sig figs 5. Counting numbers and constants have infinite significant figures – 5 people has infinite sig figs

24. Practice Identifying Sig Figs A) Clearly circle the significant digits in each of the following numbers: 0.540 30 m 46.93 L 0.004 79 g 56.00 s B) Rewrite each of the following numbers to the number of significant digits which is specified in the parenthesis: 0.012 70 (2)2,190,050 L (2) 0.005 23 g (1)3.079 s (2)

25. Rule for Multiplying/Dividing Sig Figs Multiply as usual in calculator Write answer Round answer to same number of sig figs as the lowest original operator EX: 1000 x 123.456 = 123456 = 100000 EX: 1000. x 123.456 = 123456 = 123500

26. Practice Multiplying/Dividing 50.20 x 1.500 0.412 x 230 1.2x10 8 / 2.4 x 10 -7 50400 / 61321

27. Rule for Adding/Subtracting Only place values where all measurements being added/subtracted have sig figs are utilized EX: 1002 + 1.2345 1003

28. Practice Adding/Subtracting 100.23 + 56.1.000954 + 5.0542 1.2 x 10 4 – 5.02 x 10 3 1.0045 + 0.0250